It is a pact that is part of the United Nations Framework Convention on Climate Change, which started in 1992 with the Rio Earth Summit. Technically, the Paris agreement itself is not a treaty so its adoption by America did not require U.S. Senate approval.

When Trump announced the U.S. withdrawal from the climate agreement in 2017, the move reverberated around the globe. Nearly 200 nations had committed to reducing greenhouse gas emissions under the pact when it was created in 2015, and they had set ambitious targets to keep global temperature rise well below 2°C, and ideally below 1.5°C.

The president on Monday announced his intention to withdraw the country, for the second time, from the global emissions reduction pact.